Precious metal N-heterocyclic carbene-carbaboranyl complexes: Cytotoxic and selective compounds for the treatment of cancer

A range of precious metal complexes incorporating either benzyl or carbaboranyl functionalised tethered N-heterocyclic carbenes have been prepared and fully characterised, including single crystal X-ray crystallography for one new complex. The library has been screened for their anti-cancer potential against colorectal, ovarian, cisplatin-resistant ovarian and breast cancer cell lines and their selectivity determined by comparing the cytotoxicity towards normal cells. Overall, these complexes show significant selectivity for ovarian carcinoma, and are up to 3-fold more cytotoxic than cisplatin against cisplatin-resistant human ovarian carcinoma. Upon replacing the benzyl moiety of the NHC ligand with a carbaboranyl there is a general increase observed in the potency of the complexes, with the cytotoxicity of the ruthenium complex increasing by >16-fold against human ovarian carcinoma. Generally, the rhodium complex with the benzyl tethered NHC shows the greatest selectivity for cancer, with a selectivity index of 15, which is >2x, >9x and >6x higher than that of cisplatin, carboplatin and oxaliplatin, respectively

Silver–N-heterocyclic carbenes in π–Activation: Synergistic effects between the ligand ring size and the anion

A series of 12 silver­(I)–N-heterocyclic carbene (NHC) complexes were prepared featuring five- (both saturated and unsaturated backbone), six-, and seven-membered ring ligand scaffolds. The N-substituents of the NHCs were diisopropylphenyl in all cases, while the anion was varied between bromide, acetate, and triflate. The complexes were evaluated as catalysts in the spirocyclization of 1-(1H-indol-3-yl)-4-phenylbut-3-yn-2-one to give a spirocyclic indolenine product. To our knowledge, it is the first time that a systematic study has been conducted to examine the effects of both NHC ring size and anion in this type of silver-catalyzed reaction. While the acetate and triflate complexes catalyzed the reaction to 100% conversion, the bromide complexes exhibited a significant ligand/anion effect. Reactions catalyzed by both complexes bearing the five-membered ring NHC ligands and the complex bearing the seven-membered ring NHC ligand stalled after approximately two turnovers. However, the bromide complex bearing the six-membered ring NHC ligand catalyzes the reaction to almost full conversion, similarly to the acetate and triflate complexes. This demonstrates that the NHC ligand ring size can have a dramatic effect in these types of reactions and does not necessarily display a linear correlation

The light-from-above prior is intact in autistic children

Sensory information is inherently ambiguous. The brain disambiguates this information by anticipating or predicting the sensory environment based on prior knowledge. Pellicano and Burr (2012) proposed that this process may be atypical in autism and that internal assumptions, or “priors,” may be underweighted or less used than in typical individuals. A robust internal assumption used by adults is the “light-from-above” prior, a bias to interpret ambiguous shading patterns as if formed by a light source located above (and slightly to the left) of the scene. We investigated whether autistic children (n = 18) use this prior to the same degree as typical children of similar age and intellectual ability (n = 18). Children were asked to judge the shape (concave or convex) of a shaded hexagon stimulus presented in 24 rotations. We estimated the relation between the proportion of convex judgments and stimulus orientation for each child and calculated the light source location most consistent with those judgments. Children behaved similarly to adults in this task, preferring to assume that the light source was from above left, when other interpretations were compatible with the shading evidence. Autistic and typical children used prior assumptions to the same extent to make sense of shading patterns. Future research should examine whether this prior is as adaptable (i.e., modifiable with training) in autistic children as it is in typical adults

Trust-Building in a Patient Forum: The Interplay of Professional and Personal Expertise

Online discussion forums for patients offer the benefits of community but the risks of misinformation. A physician-moderated forum may help to mitigate this tension. How do both the professional expertise of a physician moderator and the personal, experiential expertise of patients contribute to trust in a forum? A rhetorical analysis of a year of postings in an online Parkinson’s community reveals that both forms of expertise were trusted, demonstrating the possibility for them to complement each other. This study illustrates the broader ways trust is established in patient communities and offers implications for technical communicators as forum designers or moderators

UK gamete donors' reflections on the removal of anonymity: implications for recruitment

BACKGROUND: In 2005, UK legislation was changed requiring any donor of gametes or embryos used in the treatment of others to agree to the disclosure of their identity to any offspring reaching the age of 18. METHODS AND RESULTS: This paper analyses responses of a survey of existing donors' views on the removal of donor anonymity that was undertaken by the Department of Health (UK) as part of its review that preceded changes to the law on donor anonymity. The survey provides an insight into what it is about the loss of anonymity that some donors find problematic, indicating that although some donors will be reluctant to donate under conditions of non-anonymity, others have concerns about the removal of anonymity that can be addressed. CONCLUSIONS: This paper identifies factors, in particular counselling, support and better information that could maintain gamete donor recruitment in the context of the UK's policy of non-anonymous and non-remunerated donation